In a peer to peer communications system, peer communications devices may periodically or non periodically transmit peer discovery information, e.g., peer discovery signals. The peer discovery information may include, e.g., identification information, so that a receiving device may identify the transmitting peer device and establish communications if the transmitting device is of interest to the receiving device. In some systems the peer discovery information is transmitted using an omni-directional antenna. Although peer discovery signals transmitted using an omni-directional antenna may easily reach neighboring peer devices in close vicinity to the transmitting device, the range of the omni-directional antenna can be limited by transmission power constraints and the failure to focus the transmitted energy in a beam. An advantage of using an omni-directional antenna pattern is that devices within the omni-directional antenna pattern coverage area, will be able to detect each of the transmitted signals regardless of their position relative to the transmitting device.
While the use of a beam antenna pattern may provide greater range than an omni-directional pattern for a given total amount of transmission power, the use of a focused beam to transmit peer discovery signals has the drawback that nearby devices which are not inside the transmitted beam may not detect the transmitted peer discovery signals even though they are in close proximity to the transmitting device. While rotating or changing the transmission beam direction over time may have the advantage of allowing devices surrounding the transmitted device to detect the discovery signals at a greater distance than when an omni-directional pattern is used, there may be a significant delay in detection time as compared to the omni-directional case depending on the location of the receiving device and the amount of time required for the beam to compete a full rotation. This is particularly the case where multiple peer discovery transmissions are required before a decision on whether to contact the transmitting device can be made by the receiving device, e.g., because part of the full information needed for the decision is transmitted in each of the multiple different peer discovery transmission time periods.
In view of the above discussion it should be appreciated that it would be beneficial if methods and apparatus could be developed which would provide at least some of the range benefits of using beamforming antenna patterns without necessarily subjecting all receiving devices to the delays associated with having to wait for a beam to rotate around.